George Martin

At one point in the "Soundbreaking" documentary series, producer Paul Epworth describes a freshly heartbroken Adele singing him her new song, "Rolling in the Deep," pounding out the beat — and her frustrations — with her foot on a slab of wood.

George Martin, the Beatles' urbane producer who quietly guided the band's swift, historic transformation from rowdy club act to musical and cultural revolutionaries, has died, his management said Wednesday. He was 90.